Effects of fluid restriction on measures of circulatory efficacy in adults with septic shock.

BACKGROUND: The haemodynamic consequences of fluid resuscitation in septic shock have not been fully elucidated. Therefore, we assessed circulatory effects in the first 24 h of restriction of resuscitation fluid as compared to standard care in intensive care unit (ICU) patients with septic shock. METHODS: This was a post-hoc analysis of the multicentre CLASSIC randomised trial in which patients with septic shock, who had received the initial fluid resuscitation, were randomised to a protocol restricting resuscitation fluid or a standard care protocol in nine ICUs. The highest plasma lactate, highest dose of noradrenaline, and the urinary output were recorded in five time frames in the first 24 h after randomisation. We used multiple linear mixed effects models to compare the two groups. RESULTS: We included all 151 randomised patients; the cumulated fluid resuscitation volume in the first 24 h after randomisation was median 500 ml (Interquartile range (IQR) 0-1500) and 1250 ml (500-2500) in the fluid restriction group and standard care group, respectively. The estimated differences in the fluid restriction group vs. the standard care group were 0.1 mM (95% confidence interval -0.7 to 0.9; P = 0.86) for lactate, 0.01 µg/kg/min (-0.02 to 0.05; P = 0.48) for dose of noradrenaline, and -0.1 ml/kg/h (-0.3 to 0.2; P = 0.70) for urinary output during the first 24 h after randomisation. CONCLUSIONS: We observed no indications of worsening of measures of circulatory efficacy in the first 24 h of restriction of resuscitation fluid as compared with standard care in adults with septic shock who had received initial resuscitation.